Project description:Thymic medullary epithelial cell (mTEC) expression of the autoimmune regulator AIRE, and of tissue-specific antigens, is controlled by members of the non-canonical NF-kB signalling pathway, including RelB and NF-kB2. Of the genes in this pathway, RelB-/- mice develop a particularly severe multi-organ autoimmune syndrome, resembling Foxp3-deficiency. RelB-/- mice have medullary atrophy and few mTECs but the mechanism is unknown. We show that RelB is required for expression of medullary chemokines and mTEC AIRE, selection of a diverse peripheral T cell repertoire, and for peripheral Foxp3+ Treg function. Vβ families of T cells infiltrating diseased peripheral organs and thymic Treg were similarly skewed. Surprisingly, medullary atrophy results from intra-thymic granulocyte infiltration, consequent upon the Th2-mediated autoimmune disease. Dominant tolerance corrects thymic inflammatory disease and loss of thymic function. We demonstrate a reversible RelB-dependent inflammatory mechanism for loss of central tolerance associated with medullary atrophy. Thymi from 4 RelB+/- mice and 3 RelB-/- mice were profiled by microarays
Project description:Thymic medullary epithelial cell (mTEC) expression of the autoimmune regulator AIRE, and of tissue-specific antigens, is controlled by members of the non-canonical NF-kB signalling pathway, including RelB and NF-kB2. Of the genes in this pathway, RelB-/- mice develop a particularly severe multi-organ autoimmune syndrome, resembling Foxp3-deficiency. RelB-/- mice have medullary atrophy and few mTECs but the mechanism is unknown. We show that RelB is required for expression of medullary chemokines and mTEC AIRE, selection of a diverse peripheral T cell repertoire, and for peripheral Foxp3+ Treg function. Vβ families of T cells infiltrating diseased peripheral organs and thymic Treg were similarly skewed. Surprisingly, medullary atrophy results from intra-thymic granulocyte infiltration, consequent upon the Th2-mediated autoimmune disease. Dominant tolerance corrects thymic inflammatory disease and loss of thymic function. We demonstrate a reversible RelB-dependent inflammatory mechanism for loss of central tolerance associated with medullary atrophy.
Project description:Antigen presentation by cortical and medullary thymic epithelial cells (cTEC and mTEC) ensures the formation of a self-restricted and self-tolerant T cell repertoire, respectively. As such, a broad diversity of self-antigens needs to be presented by mTEC to induce T cell’s self-tolerance. Even though the expression and antigen presentation of protein coding genes in mTEC has been abundantly described, little is known of the implication of allegedly noncoding regions of the genome to tolerance induction. In this study, we focused on transposable elements (TE), which have been shown to be highly expressed by mTEC.
Project description:In this study, we used the murine (Mus musculus) medullary thymic epithelial cell line (mTEC 3.10 cell line) co-cultured with fresh thymocytes as a functional assay for mTEC-thymocyte adhesion. Then we analyzed the differential transcriptional profile of this cell line, by means of Agilent oligo microarray hybridization, comparing Autoimmune regulator (Aire) wild-type cells vs Crispr-Cas9-induced Aire KO cells. The comparative transcriptional expression signatures allowed us to find those differentially expressed mRNAs or lncRNAs between the samples tested.
Project description:10x sequencing of TSPAN8+, GP2+ or Unselected medullary thymic epithelial cells (mTEC) isolated from female C57BL/6, BALB/c, and C57BL/6 x BALB/c F1 mice with the intent to identify co-expression patterns in promiscuously expressed genes in individual mTEC.
Project description:To explore global gene expression using microarray analysis in mTEC's isolated from MBD1 WT and MBD1 KO mice mTECs were sorted by flow cytometry from 30 day old MBD1 WT and KO Mice. 4 biological replicates were performed for both MBD1 WT and KO mice (1 replicate of each failed quality control and wasd removed from the analysis).
Project description:Promiscuous gene expression (pGE) of numerous self-antigens in thymic epithelial cells (TEC) enables the elimination of self-reactive T cells. The autoimmune regulator (Aire) is the only known molecular determinant driving pGE in the thymus but the existence of Aire-independent mechanisms has been inferred. Here, we analyzed the poly(A)+ transcriptome of TEC populations by RNA-sequencing (RNA-seq) in order to reveal differential features of Aire-induced vs. –independent pGE. We report an unanticipated effect of Aire deletion on the proliferation and differentiation of cortical TEC. Moreover, the RNA-seq data reveal the breath of Aire-induced and –independent pGE in medullary TEC (mTEC) subsets and the extent of thymic peripheral tissue representation. The results suggest that Aire-induced promiscuously expressed transcripts affect several functions with far reaching biological consequences in mTEC. High-throughput characterization of TEC transcriptomes will enable progress in understanding TEC biology and the establishment of self-tolerance. The mRNA profiles of cTEC, mTEClo and mTEChi from 6-8 week-old wild type (WT) and Aire-/- (KO) mice were generated by RNA-sequencing using Illumina HiSeq2000.
Project description:Analysis of gene co-expression patterns in TRA-specific medullary thymic epithelial cell (mTEC) subsets. The whole genome gene signatures of purified mTEC subsets respectively positive for the TRAs Gp2, Pdpn, Cea1, Gad1, Ins2, Tspan8 were compared to their corresponding TRA-negative mTEC subset control. Results provide the enriched and depleted gene expressions in the different subsets. Total RNA obtained from FACS isolated mTECs positive for the respective TRAs were compared to their TRA-negative mTEC subsets using specific antibodies (Pdpn, Gp2, Cea1, Tspan8) or reporter mice (Gad1, Ins2).
Project description:We used Affymetrix microarrays to understand the genome wide differences in Adult and fetal cortical thymic epithelial cells (cTEC) and medullary thymic epithelial cells (mTEC)